Patient stretchers and hospital beds have frequently included tiltable head, middle, and foot sections. Such types of beds or stretchers are shown in U.S. Pat. Nos. 3,611,453; 3,972,081; and 4,025,972. When such tiltable tops are power driven, there is frequently a problem of holding the tiltable top in a given position for long periods of time. When such power drive is the only support for the tiltable top, excessive strain is put on the linkages and power components.
Some unpowered stretchers and beds have proposed the use of props and limit stops against which the weight of the tiltable top and patient could rest. However, when there are limit stops for different height locations, such limit stops do not work well with power driven pivot tops. Extensive switching and electrical cutoff are necessary to insure the power drive will stop at the particular limit stop without crushing down against the limit stop and possibly bending or distorting certain structural features of the stretcher or bed.